It is known to provide outsoles of items of footwear, such as shoes and boots, with ground engaging elements having certain ground-engaging characteristics. For example, hiking and sports shoes having outsoles with spikes, studs or cleats to improve traction and provide anti-skid properties, and tap dancing shoes having taps attached to the outsoles with different sound properties, are known. However, there are circumstances where such ground-engaging elements should be disabled or changed such when a wearer of the item of footwear moves from an outdoor to an indoor location having a surface that could be damaged by spikes, studs or cleats, or when a different frictional characteristic is required. Under such circumstances, it is desirable to disable the ground-engaging elements at will for certain periods of time and thereafter reactivate them as needed. It is also desirable to change the ground-engaging property of the item of footwear without removing that item of footwear and donning another item.
Accordingly, some solutions have been provided in the prior art which include complex systems providing user activated stud retraction mechanisms. However, these are not found on the market given their generally poor overall performance and high manufacturing cost.
Other, more practical systems have also been provided which include attachments for outsoles, the attachments being moveable to expose different surfaces having different properties as required.
In U.S. Pat. No. 6,675,504, granted to Biancucci in January 2004, a shoe sole is provided with spikes projecting from one face of a support means. The support means is pivotably attached to the sole and is movable between a first position in which the support is fully received in a first recess provided in the ground contacting face of the sole with the spikes projecting outwardly, and a second position in which the support is fully received in a second recess with the spikes extending into said second recess. As only one of the recesses is used to receive the support means at any one time, the unused (empty) recess may fill with soil, snow, ice, and other debris while walking with the spike supporting means in the first or second positions. Moreover, the support means has a limited efficient area as it must be half the size of the total recess surface to enable it to flip from one recess to the other.
International publication No WO2004/041016 (published in May 2004) from the same inventors and applicants as U.S. Pat. No. 6,675,504 describes a similar concept to U.S. Pat. No. 6,675,504 where a sole is provided with a recess together with a support means receivable in the recess and having spikes projecting from one of its surfaces. In WO2004/041016, the support means is pivotably attached to the sole so that it can be lifted into and out of the recess. The attachment mechanism allows the support means to be rotated to expose its other face so that it is moveable between a first position in which the support means is fully received in the sole recess with the spikes facing outwardly, and a second position in which the support means is received in the recess with the spikes extending into the recess. However, the support means does not appear to be removable from the recess without the use of a tool to prise it out of the recess. This would mean that a wearer of an item of footwear with this sole would need to carry a tool with them. Furthermore, the pivoting mechanism is set into a recess which must necessarily be larger than the mechanism itself. The recess is likely to fill with soil, snow, ice, and other debris while walking with the spike supporting means in the first or second positions.
U.S. Pat. No. 6,360,455 entitled “Pack Boot with Retractable Crampons” issued to Seo on Mar. 26, 2002 also teaches a dual cavity flip concept with traction devices of still smaller effective surface than U.S. Pat. No. 6,675,504 and sharing similar disadvantages.
U.S. Pat. No. 4,745,692, granted to Liao on May 24, 1988, describes an anti-slip device comprising a slip-proof member pivotably mounted to the bottom of a shoe. The slip proof member has prongs extending from one of its faces and is receivable in a recess in the bottom of the shoe in one of two positions: one position with the spikes pointing outwardly and the other position with the spikes being received into the recess. However, the pivoting mechanism of U.S. Pat. No. 4,745,692 is complex and the design of the anti-slip device prone to accumulate dirt, snow or ice in the recess and in the pivoting mechanism which could cause jamming of the device and render operation difficult.
European patent application No EP1,044,621 (published on Oct. 18, 2000) discloses a shoe having a recess in its heel. The recess contains a receiving member for receiving a reversible element which has one spiked surface and an opposed smooth surface. The reversible element also has a tapered outer edge which corresponds with a similarly shaped groove in the receiving member. The element can be slid into the receiving member in two positions to expose either the spiked or the smooth surface. A hole is provided through the heel and the receiving member into which a locking member (e.g. a screw) is inserted to secure the reversible element in the receiving member. As the locking member is separate from the reversible element and the receiving member, it can become separated and lost. Also, adapting the heel of a shoe to include a receiving member would increase manufacturing costs. Finally, manipulating such a locking member is cumbersome for the wearer of the shoe.
U.S. Pat. No. 2,776,499 granted to Giuntini on Jan. 8, 1957 provides a reversible plate extending from the heel to the toe of an item of footwear. The plate includes cleats on one of its surfaces and is hingedly attached to the underside of the sole under the arch. The plate can be moved about a transverse axis between two positions: one position in which the plate overlies the front and rear portions of the sole with the cleats exposed and a second position in which the front portion of the plate is folded back over itself to hide the cleats by nesting the cleated face of the front portion into cleated portion of the rear portion. This necessarily increases the height of the heel portion of the item of footwear. Also, the hinge portion is vulnerable to collect debris which would impair the hinging mechanism.
Therefore, it is desired to overcome or reduce at least some of the above-described problems.